WASHINGTON -- A bipartisan coalition of senators has reintroduced legislation that calls for eliminating the dollar bill and replacing it with the $1 coin.

The Currency Optimization, Innovation and National Savings Act (S. 1105), or COINS Act, was introduced on June 6 by Sens. Tom Harkin (D-IA), John McCain (R-AZ), Mike Enzi (R-WY), Tom Coburn (R-OK) and Mark Udall (D-CO). The lawmakers first introduced the COINS Act in February 2012. But it, and companion legislation introduced in the House of Representatives, failed to become law.

"The benefits of the dollar coin have long been recognized by reputable sources such as the General Accounting Office as a smart investment for our country," said Harkin. "The experiences of countries around the world reveal that transitioning to dollar coins will generate significant savings to taxpayers without disrupting businesses or consumers. I am hopeful that this bipartisan legislation will continue to gain traction in Congress."

The COINS Act would require that the Federal Reserve Banks stop issuing $1 notes four years after enactment of the legislation, or when circulation of $1 coins exceeds 600 million annually -- whichever comes first. The Federal Reserve would also be required to undertake efforts to improve the circulation of, and remove barriers to the circulation of, the $1 coin, including outreach and education programs. The bill specifies, however, that $1 Federal Reserve Notes may continue to be produced and issued to meet the needs of collectors.

The COINS Act must be approved by the Congress and signed by the President to become law. It has been referred to the Committee on Banking, Housing and Urban Affairs.

The bill's sponsors point to the fact that the GAO has studied the issue nine times over the last 23 years and has reached the same conclusion -- the U.S. should transition away from a $1 note and move to a $1 coin. It projected that the estimated annual savings would range from nearly $200 million to more than half a billion dollars from making the transition.

While dollar bills last only 18 months or so, the COINS Act sponsors point out, a $1 coin can remain in circulation for more than 30 years. And while billions of dollar notes are shredded and sent to landfills each year, $1 coins are 100% recyclable and can be melted down and forged into new coins.

The lawmakers also emphasize that the move would benefit cash-intensive businesses, like vending machine operations, since coins are far less expensive and cumbersome to process than notes.

The COINS Act is supported by the Dollar Coin Alliance, a coalition of American small businesses, budget watchdogs and trade associations lobbying for legislation to retire the $1 bill. Its members include the National Bulk Vendors Association, Southeastern Pennsylvania Transportation Authority, Tri-State Automatic Merchandising Council and United Steelworkers. Separately, the American Amusement Machine Association has been meeting regularly with lawmakers in Washington to discuss the benefits of greater dollar coin usage.

"Modernizing our currency is long overdue. In a time of fiscal restraint, Congress must take a hard look at the billions sitting right in front of them," said former Congressman Jim Kolbe (R-AZ), co-chair of the DCA. "This is a common sense budget solution that saves billions without raising a single tax or cutting a single program."